Coin counter and discriminator



Jan. 7, 1958 A. H. FAULKNER COIN COUNTER .AND DISCRIMINATOR Fiied Aug. e. 1953 INVENTOR. ALFRED H. FAULKNER ATTY.

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United States Patent COIN V COUNTER AND DISCRIMINATOR Alfred H. Faulkner, Chicago, Ill., assignor to General Telephone Laboratories, Incorporated, a corpomtwn of Delaware Application August 6, 1953, Serial N0. 372,700

17 Claims. (C1. 179-6.3)

The present invention relates in general to a coin munter and dis'criminator for coin controlled mechanisrns and more particularly t an electronie and electrical means for discriminating between a signal generated 011 deposit of a coin in a coin receiving mec'zhanism and a signal generated otherwise and for determining the value of a deposited coin automatically from |the number cf signals generated thereby.

With the advent :of coin eontrolled meehanisrns the roblem of distinguishing between and determining values of deposited coins has received mueh attention. C0- existent therewith has been the problem cf automatic control in response to the deposit of a pwper va1ue cf coins and the roblem of preventing false operation due to a simulated deposit. As widespread use :of telephone paystations has provided great impetus to the develop ment of coin -controlled mechanisms wherein the deposit of a plurality of coins is required before a connection can be established, the present invention Will be discussed in conjunction therewith. A telephoe paystation coin receiving mechanism for nickels and dimes of the general type -disclosed in Patent N0. 1,043219, issued to Forsb erg November 5, 1912, having a coin transmitter acoustieally eoupled to a gdng struck by a falling nickel 01' dime as -shown in Patent N0. 2235,648 issued to Shann Mareh 18, 1941, may be considered as a typical coin receiving arrangement for the present invention. In this type cf coin receiving mechanism, the deposit 0f a nickel in its respective ehute results in the nickel striking a gong once and the deposit -of dizne in its respective chute striking a. gong tw-ice. The praetice generally existing is that 011 local calls from a prepay paystation a eonneetion -is established automatically by the cal1ing pavty simply by depositing a coin, which either removes a shunt from the dial springs er -completes a eircuit through the dial springs, and then proceeding to dial. In postpay paystatin systems, dialling may be initiated before deposit cf a coin, but a talking circuit ean not .be completed until a coin is deposited. F0r toll ca1ls from either prepay or postpay paystation systems, a conneetion must be made to an operator and then on the request of the operator, the calling party mus deposit a requh:ed value of coins which then must be identified by the operator no determine their value. G-enerally, this is done by transmitting the tone, resulting from the coins striking a gong in the ehute, over a coin transmitter located in the ehute and the trunk to the operators position. The -Operator is then presented With the problem 0f discriminating between either the frequencies or the number of tones transmitted by the coin transmitter 011 deposit of eaeh coin. The eonditions described are further complicated by changing economic conditions resulting in rate raises for loeal ealls thereby rendering useless much f0rmer equipment er necessitating expensive -changes to adapt paystation devices to new eon-ditions even for automatic eontrol of local calls. For example many paystations former1y enab1ed to allow the completion 0f a local connection on deposit 0f a nickel now require the deposit of a dime for the same Service. Therefore the nickel chute must be blocked, often -resulting in the loss of revenue, or expensive changes made to allow automatic =completion cf a connection 011 deposit of two nicke1s. If neither the nickel chute is blocked 01' the expensive changes made, the local connection must be completed by an 0perator, when the rate is raised t0 -a dime, thereby giving rise to the af-oyen1entioned and other roblems concerning operator control.

Many atternpts have been made to provide eompletely automatie control in response 1:0 the deposit of coins for the purpose of permitting the establishment of a counection from a paystation, but equipment for determining the vra1ue of deposited coins has heretofore been cumbersome, bulky and consequently expensive, while a feasible inexpensive system such as the present invention for providing automatic control by means of the tone signa1 generated on deposit of each coin is extremely difiicult t-o devise. The present invention however, overcomes these difiiculties by pro-viding a simple electronic coin munter arranged to be operated in accordance with the nurnber cf tone signals generated by a coin striking its associated gong, while falling through the chute, t0 provide c-ompletely automatic control and allow a connection be completed. As provided in the aforementioned patents each coin in fall-ing Ihrough its chute strikes a gong and produees a tone or number of tones corresponding to the value cf the coin, which are picked up by the associated coin transmitter and transrnitted as a corresponding number cf oscillat-ions of a particular frequency over a trunk circuit t-o the central o-fiice. The eleetronic counter of the present invention then makes an automatic count of the nurnber 0f oscillations cf the particular frequency to determine the value of coins deposited and for eontrolling equipment for permitting a connection to be established. Oscillations generated as a result of tones, noises 01' Whistling applied to the voice transmitter either purposely to simulate the deposit of a coin or as 0ceasionally aocidentally occurs are prevented from aifecting the electronic coin ceunter by circuit arrangements and innovations such as Will be described in greater detail in other portions -of this specification. It Will be understood that the terrn coin used herein is used in its generie sense.

Accordingly, 0ne of the objects of this invention is to provide 21 novel electronic means for counting the value -of coins deposited in a coin receiving mechanism.

Another objeet is to prevent tones generated by means other than the depesit cf a coin from enabling the operation of any equipment.

Another object cf this invention is 10 provide novel means for automatically enabling the required equiprnent on deposit of -a proper value of coins.

A further object is to provide a novel coin counter Operated in accordance With the tone signals generated by a coin deposited in a coin receiving means.

Still a fur-ther object is to provide means for discrin1- inating betwen tones genera.ted by the deposit of a coin in a coin rcceiving means and tones genetated through other means.

Another object of this invention is to provide a mini' mum of simple equiprnent of a nove'l and inxpensiVe type for the above services and operations.

One 0f the features of this invention i's a simplex circuit of the equipment upon deposit of coins having a prede termined value.

Still anothcr feature of this invcntion is the circu1t a1- rangement for providing automatic control on the deposit of the proper value of coins.

The drawing shows a typical paystation circuit (llS- closing the necessary circuit innovations therein for discriminating between tone signals generated in the voice transmitter and the coin transmitter. It also shows a line circuit and linefinder 4 and a selector 9. The line c'ucuit and linefinder are shown as cornbinecl in one blocl form while the selector is shown by itself in block form The operations of the line circuit, linefinder and selector are all old and well-known in the art and will be discussed herein only in so .far as they pcrtain the invention. A repeater in which are located the electromc tubes and circuits for counting the number 0f deposited coins and equipment controlled thereby on deposit of a predetermined value of coins fo1 permitting the establishment of a connection is located between the linefinder and selector, which are cornrnonly known as a linder selector link. The finder selector link is of any well known standard type in which a switching relay in the fincler is operated to switch thetrunk through the finden The link is arranged so that the trunk is first switched through to the repeater and the findet switching relay is held operated frorn there. After the coins are deposited and counted the repeater and the electronic counter therein are disconnected, and the trunk is switched through to the selector for operating the selector line relay to seize the selector. Dial tone is then sent back to the calling party in any well known manner. The finder switching relay is then bald operatecl from the selector in accordance With standard practice.

The present system uses a condenser resistor simplex circuit network between the two sides of the line 50 to balance the line with respect to any voltages produced by tones generated in the voice transmitter 35 to thereby enable a neutral voltage condition to be produced between resistors 22 and 22 and 0n the grid of amplifier tube A in the paystation repeater. On deopsit of a coin however, initiating voltages are provided to the grid of this tube from the same point between resistors 22 and 22, as transforrner 15, the primary of which is approximately the same ohrnic value as coin transrnitter 25, reproduces the variations in voltage then appearing acro'ss coin transmitter 25 to provide voltages of the same sign from both sides of line 50 and therefore at the point between resistors 22 and 22 where the grid of the tube A is connected.

The repeater 100 is seized when the switching relay in the linefinder is operated in any well-known manner on initiation of a call and before the deposit of a coin. A relay and an impedance are used in the repeater in place of the conventional two winding relay which might act like a short circuit transformer and shunt the simplex. Operation of the relay on seizure closes a circuit to a slow-to-release relay which operates for providing voltages to the tubes so that they are initially in a conducting state. A second electronic tube B which is a double triode has the grid of its right triode coupled to the plate circuit of amplifier tube A. The right triode is arranged as a cathode follower and is coupled to the grid of the work relay control tube C through a 220,000 ohms resistor 55. The cathode follower is also comnected to a parallel-T frequency selective network which is in turn connected to the left triode of tube B. The left triode is also a cathode follower having its cathode coupled to the grid of the amplifier tube A. The comstants of the network are chosen to produce a null point at 1200 cycles corresponding to the average frequency of tone produced by the nickel and dime gong. As the network offers the greatest impedance to a 1200 cycle frequency, little interference will be produced over the coupling circuit to tube A to an incoming 1200 cycle fre- 4 quency over the simplex circuit and this frequency will be amplified. Therefore any stray voltages which by chance may appear over the simplex circuit and on the grid of tube A such as generated by the opening of the coin springs CS5 on deposit of a coin or operation of the dial springs will be further discriminated against. Since the amplifier is selective to frequencies close to 1200 cycles, and its gain drops to one half its maxirnum valuc at 1050 cycles and 1350 cycles, the grid of tube C Will be swung sharply positive and negative only at such times as the coin transmitter is subject to 1200 cycle tone. Resistor 55 is provided in the grid circuit of tube C to limit the flow cf grid current on the positive half of the cycle, thus preventing any substantial increase in the tubes plate current. Thus during any time period where a 1200 cycle frequency is produced and amplified by the arnplifiers the average current passing through tube C Will be decreased sufliciently to allow the release of work relay 40. The work relay 40 provided in the plate circuit of the last tube is normally operated when the repeater is seized and the +150 volt plate supply voltage is applied to the tube C to cause it t0 cond'uct. This relay in turn by releasing on the 1200 cycle tone and by its reoperation thereafter controls the operation and pro paration for operation of other relays for seizin'g the selector to signal the calling p'arty by sending back dial tone that the equipment is prepared to receive dial pulses and for permitting the calling party to establish a C'0I'l nection. Work relay 40 may be made sligh'tl'y slowtorelease so (hat if cven severe pounding o'n the coin box induces a momentary tone of 1200 cyc1es in coin transmitter 25 it will not release sufiiciently to operatc any contacts.

Therefore if a dime is deposited in the coin chute the coin transmitter will generate 1200 cycles frequencies at two discrete time intervals which in turn produces a voltage which is amplified by the tubes and applied to the grid of tube C for controlling the work relay correspondingly. The work relay in turn operates the previously mentioned controlled relays to seize the selector, which signals the calling party by sending dial tone back to the paystation to indicate that a connection may now be automatically established. However, as a nickel provides only one 1200 cycle tone the work relay is not released and operated enough timcs to operate all relays necessary to permit the signalling of the calling party and to allow establishrnent of a connection unless a second nickel is deposited to provide a second 1200 cycle tone. In this manner a count is made of the value of the deposited coins and the equipment controlled for allowing or preventing further operation. It will be observed that the human problem cf distinguishing between two tones generated in quick succession 011 the deposi t of a dirne is eliminated by the use of electronic equ1pment.

T0 illustrate the manner of operation of the prcsent invention, assurne that a calling party at a paystation 2 Iras initiated a call by lifiing ihe handset to cause the lrnefinder 4 to find the line associated with the paystation in the finder bank in any well-known manncr. The line loop 50 is extended by operation of the switching rclay in linefincler 4 in any well-known manner to relay 10 and unpedance 20 in the repcater to complete a circuit frorn ground on the right side of impedance 20, conlacts 96, over the +L line of trunk 50, through dial pulsing springs 1 and coin springs CS5, contacts 7, coil 8, the voice transrnitter 35, the coin transmitter 25 and the primary of transforrner 15 in parallel, the -L line of trunk 50, contaets 96 to battery on the right sidc cf relay 10. Relay 10 on operating closes contact 11 to complctc an obvious cir cuit for operating relay 30 which on operating closes contacts 31, 32 and 33. Contacts 33 on closing provides a holding ground for the switching rclay in the linefinder. Closing of contacts 32 complctes an o'ovious circuit over contacts 91 for supplying Volt positive battery to, the plates of tubes A, B and C. I t has been found preferable to use a 12AU6 tobe for tube A; a 12AT7 tube for tube B and /2-12AT7 tube for tobe C. The circuits of said tubes are arranged so that they comduct on the application of the 150 volt positive battery.

It Will be noticed that at this time a ground return is provided from ground on the left hand side of the coin magnet 9 through the secondary transformer 15 to a point between resistors 3 and 3 and condensers 6 and 6 bridged across trunk 50. As previously mentioned A. C. noises may be deliberately generated in the voice transmitter to simulate a deposited coin. Resistors 3 and 3' are of the same value preferably each around 22,000 ohms While condensers 6 and 6' are preferably each in the neighborhood cf .01 mf. Resistors 22 and 22' bridge the trunk 50 in the repeater and are of a high resistance preferably in the neighborhood cf 27,000 ohms to reduce transmission losses. It will be noticed that the trunk 50 is now balanced with respect to the generation of A. C. noises in the voice transmitter 35 and they therefore produce voltages of equal and opposite polarity across resistors 22 and 22 at the point where they are counected to the grid of tube A. Such A. C. noices therefore have no eifect 011 the conductive state of this tube. Coin springs CS5 shunt dial spring 1 before deposit of a coin t prevent dialling.

New if the calling party inserts a nickel in the coin chute adapted to receive the same, coin springs CS will open to remove the shunt from dial springs 1 and tones of various frequencies including a 1200 cycle tone will be generated in coin transmitter 25. As the nickel strikes its associated gong only once, only one 1200 cycle tone is generated. The variation of voltage appearing across coin transmitter 25 at that time is reproduced across transformer 15. This voltage condition will be reproduced 011 trunk 50 to give voltages of the same sign 011 both sides of the trunk so that the voltage at the grid connection of tube A at the point between resistors 22 and 22 Will vary both positive and negative and be amplified accordingly by tube A. The output cf tube A is coupled to the grid of the right triode of tube B. As the parallel-T frequency selective network coupling the cathode of the right triode of tube B t0 the left triode of tube B is arranged to greatly impede frequencies in the neigbborhood of 1200 cycles, othef frequencies will be fed back to the grid circuit cf tube A, from the left ttiode of tube B and Will greatly impede the amplification of those frequencies by tube A. Therefore only the voltages resulting, from the 1200 cycle tone generated in the coin transmitter 25 Will be amplified sufficiently to affect the conductive state of tube C when fed into tube C across coupling Condenser 77 and resisto1 55. The amplified voltage fed into tube C of course cannot raise the current passing through tube C 011 the positive half cf the cycle and lowers it substantially during the negative position of the cycle to substantially decrease the average current flowing in the tube during the duration of the 1200 cycle tone. The frequency selective network ai ds in discriminating against tones or voltage pulses induced anyvvhere in the paystation circuits.

As relay 40 operated when tube C became conductive it closed contacts 41 to operate relay 60 over contacts 31, 92, 41 and 75. Relay 60 closecl contacts 61 and 63. Relay 60 is therefore held operated over cor 1tacts 31, 92, 71, 61 and 75. Therefore the 1200 cycl e tone which is fed into tube C results in lowering the average current flowing through tube C to a point where relay 410 is caused to release to close contacts 42 to operate relay 70 over the following circuit: ground, contacts 31, 92, 42 and 63. Relay 70 011 operating close s contacts 72 to compl ete its own holding circ uit over contacts 31 and 92. At comtacts 71 it opens the holdi ng cir cuit fo1 relay 60x which releases. Relay 70 also closes contacts' 74 so that when the tone has oeased and the tube C returns to a concluctive hovv ever is held operated from the selector.

state, and r el ay 40 reoperates and closes oontacts 41, re-

lay will now operate over conta ets 31, 92, 41 and 74 to close contact 81, and 82,. Relay 80 is hel d operated over contacts 31, 92 and 82. Dial tone is not returned or an impulsing circuit prepared to p ermit automatic operation cf any switches until relay is operated. Therefore a coin of the value of one nickel deposited in the coin chute will not permit the calling party to establish a Connection. The calling party must now deposit another m'ckel to again cause the release of relay 40 in the manner described. As relay 40 is released the second time to again close contacts 42 a circuit will now be completed over contacts 31, 92, 42, 62 and 81 for operating relay 90 which operates to close contacts 93 to complete its own holding circuit and. open the holding circuit to relay 80 which releases. It also opens contacts 91 to remove the 150 Volt positive battery otential from the plates 0f the tubes and'extinguish them and release relay 40. Relay 90 on closing contacts 94 now completes an operating circuit for relay 95 which operates and closes contacts 97 and 97 to switch the trank 50 through to the selector line relay for operating it and seizing the selector 9. Relay 95 also opens springs 96 to disconnect re1ay 10 and release repeater Relay 95 locks through contacts 98 and contacts 33 of slow-to-release relay 30. Dial tone is now sent over the coil and lower winding of the selector line relay and over loop 50 back to the paystation so that the calling party knows that he may initiate dialling over the impulsing cir cuit to the selector line relay. The selector lin e relay ox 1 operating cl oses a circuit to a hold relay as is standard practice which in turn sends ground back to hold operated the switchlng relay in the linefinder, and to close another locking circuit for relay 95 over contacts 98 to hold relay 95 after slow-tcrrelease relay 30 releases. When the trunk 50 was switched through to the selector and contacts 96 opened, relay 10 releases to open the circuit to relay 30 which in turn releases to open the holding circuit to relay 90. Relay 90 at contacts 94 opens the original operating circuit to relay 95 which When the parties replace their handsets a t the termination of the call the switches wi1 be released in any well--known manner to release relay 95.

If a dime is deposited in the coin chute instead of a nickel the same gong i s struck twice to create two 1200 cycle tone splashes in the coin transmitter 25 at two discrete time intervals. These two 1200 cycle tone splashes result in the aforedescribed operation in the same manner as the dep osit of two nickels. In this way the determination of the value of the deposited coin is made and the equipment cont rolled to enable the completion of a connection.

, Attention of the reader is directed to the fact that the described invention may easily be adapted to count all values of coins by applying appropriate tone signals to the coin counter and thereby eliminate many problems inherent in both automatic and operator -controlled toll connections and further eliminate many roblems ot' adapting standard paystation systems to changed require-' ments for local calls.

It is understood that although what I have described is the preferred embodiment of my invention the scope of my invention is to be defined by the following olaims.

What is claimed is:

1. A combination adapted for use with a coin receiving mechanisrn havi ng means associated therewith for generating a current in an associated circuit on deposit of a coin in said receiving mechanism, said current being generated a number of times corresponding to the value of the depo sited coin, other means associated With said circuit for generating currents in said circuit, the improve meint cornprising means for producing at a predetermined point in said c ircuit a first vol tage condition when said curr ents aregenerated by said other means, me ans associated with said firsf gerier'tirig' fiie.ris fot jiroducing voltage condition diflerent than said fitst' v'o1tage cox'idition at said point in said circuit if a currenf is giatiejfztt'd by said first means on deposit of a coin, said difier*c'xit voltage condition produced thereby at said point a number of times corresponding to the number of currents genh3fafcl by said first mpans, a conditioned electronic tube arfaqgefnfi't, hiefis f01" elliplyiflg said vo1tage conditions to said tu'be' atlaligen'ier'lt, said first voltage conditi m when gipiicd to said tubs arrangement incapable; of changing S'aidj1 ibe arrangeirient q'ondition, said diifer'ent vo1tage o fiditioii 1:vroduc'ed at said predetermined point when ap fallecl to sid tu bp afrangetrierit changing said tube an rang ement con'dition, a1id niatis dperated by said electxqri1ic tub e arfarige'ment whe1i its c'oii ditiqrl is changed by said a'pplied different voltage condition for' cr'itirjg the value of a deposited coin in said receiviug mechanim as said last 11'1eeing is oper ated a nmnber of times depending 'u1ioii the xiibi of tims said tube arrangement conditi'0rj is chan'gied. y

2. A combiriafion adapfe'd fo'r' us'e with adoin receiving niebchanism havii1g' a coiri tra'fispni tier' associat ed therewith whereby a cuf1ent is gendraited iri ari associated paystation circuit on deposit of a coin in said nie'chariisrri, said current being generated a numbe1 of tiriies dep'eiidarfi on the value of a deposited coin, said paystati0n cir'cu'it h'v ing a voice transmitter associated therewith whereby cm rents are generated in said paystation circuit, tbe improvement comprising means for completing said paystation circuit, an electron tube arrangement, means operated on completion of said paystation circuit for conditioning said electron tube arrangement, circuit means interconnecting said eiectron tube Arrangement and said paystation circuit, said paystation circuit including means for producinga neutral voltage condition in said last circuit means if currents a1e generated in said paystation circuit by said voice transmitter, means for producing a number of effective voltage conditions in said last circuit means when said currents are generated by said coin transrnitter, the number of said eflective voltage conditions corresponding in number to the value of a deposited coin, said electron tube condition varied only by said eficctive voltage conditions so that said tube condition is varied a number of times corresponding to the number of eurrents generated by said coin transmitter on deposit of a coin, and means operated when said tube condition is varied a predetermined number of times for enabling said paystation circuit to be extended and to determine the value of a coin deposited in said receiving mechanism.

3. A combination adapted for use with a coin receiving mcchanism having a voice transmitter and a coin transmitter associatcd therewith, said coin transmitter arranged 10 generate, in a circuit associated therewith, voltages of a predetermined frequency on deposit of a coin in said receiving mechanism, said voice transmitter arranged to generate voltages of said predetermined frequency and other frequencies in said circuit, the improvement comprising means associated with said circuit for balancing said circuit with respect to voltages generated by said voice transmitter, an electron tube amplifier arrangement tuned to amplify only voltages generated by said voltages of a predetermined frequency, said circuit and said elect.ron tube arrangement interconnected to thereby amplify voltages of said predetermined frequency in said electron tubc arrangement when generated by said coin transmitter on the deposit of a coin, said means for balancing said circuit disabling said tube arrangement with respect to voltages generated by said voice transmitter 110 thereby prevent amplification of said voltages, and means operated by said amplified voltages a number of times corresponding 10 the nurnber of times said voltages of a predetermined frcquency are generated by said coin transrnitter for counting the value cf coins deposited in said receiving means and fo r enabling the cxtens ion' cf said ci rcuit and for permitting intelligible voice currents to be generated by said voice transmitter and transmitted over said circuit.

4 A combination adapted for use with a coin receiving means having a voice transrnitter and a coin transmitter associated therewith, comprising a circuit completed through said voice transmitter and said coin transmitter, a transformer having a pn'mary winding associated with said coin transmitter for reproducing voltages generated in a portion of said circuit by said coin transrnitter on deposition of a coin in said receiving means, and a con denser resistor network connectecl across said circuit and associated with said voice transmitter for maintaining said circuit in balance with respect to voltages generated in said circuit by said voice transmitter, the secondary of said transformer connected at a predetermined point in said condenser Tesistor network for reproducing the voltages generated by said coin transmitter in another portion of said circuit.

5. A combination adapted for use with a coin receiving means having a voice transmitter and a coin transmitter associated therewith, comprising a series circuit including said voice transmitter and said coin transmitter, a simplex circuit, and means superimposed upon said series circuit for producing a voltage at a point in said simplex circuit only from tones generated in said coin transmitter 011 deposit of a coin in receiving means.

6. A co'mbination adapted for use with a coin receiving me'ans having a coin transmitter associated therewith and arranged to generate voltages of a predetermined frequency in an associated circuit, the number of said Voltages corresponding to the value of a coin deposited in said receiving means, the improvement comprising an electron tube arrangement connected over said circuit to said coin transmitter and arranged to amplify only voltages corresponding to said predetermined frequency, and means operated by said amplified voltages to determine the value of coins deposited in said coin receiving means.

7. A combination adapted for use with a coin receiving means having associated therewith a coin transmitter for producing in an associated circuit voltages of a predetermined frequency and corresponding in nurnber to the value of a coin deposited in said receiving means, comprising means operated only by the produced voltages of a pre' determined frequency in said circuit for counting the number cf said voltages, and means automatically operated by said last means in accordance with the number of said voltages produced in said circuit for determining the value of a coin deposited in said receiving means.

8. A combination adapted for use with a coin receiving mechanism having means associated therewith for generating in an associated circuit voltages of many frequencies and means associated therewith for generating in said circuit voltages of a particular frequency on deposit of a coin in said receiving means which frequency may also be generated by said first means, comprising means for automatically discriminating between voltages generated by said first means and voltages generated by said second means an deposit of a coin to effectively squelch voltages generated by said first means regardless of the frequency thereof, and means operated in accordance with the number 013 voltages generated by said second means for automatically determining the value cf a coin deposited in said receiving mechanism.

9. A combination adapted for use with a coin receiving mechanism having associated therewith means for producing in a circuit voltages corresponding in nurnber to the value of a coin deposited in said receiving mechanisrn and other means associated therewith for producing said first and other voltages in said circuit, comprising means automatically operated in accordance with the number of voltages produced in said circuit by said first means for determining the value cf a coin deposited in said receiving mechanism, and means effective on production of said first and other voltages in said circuit by said other means for disabling said last means only with respect to the Voltages produced by said other means.

10. A combination adapted for use With a coin receiving mechanism having associated therewith means for producing a number of voltages of a particular frequency the number of Which voltages correspond to the value of a coin deposited in said receiving mechanism and other means for producing voltages of many frequencies including said voltages of said particular frequency, comprising means associated with both said means and effective for counting the number of voltages produced by said first means only, and means automatically operated by said counted voltages and in accordance with the number thereof for determim'ng the value of a coin deposited in said receiving mechanism.

11. A combination adapted for use with a coin receiving mechanism having means associated therewith for generating in a circuit voltages of a particular frequency corresponding in number to the value of a coin deposited in said receiving mechanism and other means associated therewith for generating voltages of many frequencies including said particular frequency in said circuit, comprising means associated with said circuit for producing an efiective voltage in said circuit only from voltages generated by said first means to thereby discriminate against voltages generated by said other means, and means autcr matically operated in accordance with the number of said eflective voltages reproduced in said circuit for determining the value of a coin deposited in said receiving mechamsm.

12. A discriminator adapted for use With a coin receiving mechanism having associated therewith means for producing in a circuit voltages of a particular frequency on deposit of a coin in said receiving mechanism and also having associated therewith means for producing in said circuit voltages of a number of frequencies including said particular frequency, and comprising means associated with both said means for producing efiective voltages from voltages generated in said circuit by said first means only.

13. In a telephone system, a paystation telephone having a coin transmitter controlled by the tone generated on deposit of a coin to generate a fluctuating current of a particular frequency in an associated circuit, a calling device and the usual talking instrumentality at said paystation, means controllable by said device for extending connection to a called line from said paystation, counting means, means for transmitting each fluctuating eurrent generated in said circuit by each deposited coin to said counting means, means controlled by said current to operate said counting means to determine the value of deposited coins, and means controlled by said counting means for connecting said calling device to said means controllable thereby to permit the extension of a connection to a called 1ine only when coins of a predetermined value have been deposited.

14. In a telephone system, a paystation telephon having a coin transmitter controlled by tones generated by a deposited coin to produce a number of fluctuating currents in an associated circuit corresponding in number to the Value cf a deposited coin, a calling device and the usual talking instrumentality at said paystation, rncans controllable by said device for extending from said paystation a connection towards :a called line, electronic counting means, means for transmitting the fluctuating currents generated by each deposited coin over said circuit to said counting means, said counting means operated by said transmitted currents in accordance with the number thereof to determine the value of deposited coins, and means operated if said electronic counting means is operated by said currents a predetennined nurnber of times for connecting said calling device to said connection extension means to thereby permit the extension of a connection to a called line only when coins of a predetermined Value are deposited.

15. In a system such as claimed in clajm 14, means for preventing the transmission of said currents to said electronic counting mea.ns when tones are produced for controlling said talking instrumentality.

16. A system such as claimed in claim 14 in which said electronic counting means includes a frequency selective network for enabling the operation of said counting means only if said alternating currents am of a predetermined frequency.

17. For use in a telephone system wherein a substation has associated therewith a receiving meang and the usual coin transmitter whereby a fluctuating current is produced a number of times corresponding to the value cf a coin deposited in said receiving means and wherein said current if produced as a resu1t of. a coin deposit are of a particular frequency and if produced by other than a coin deposit may be cf any other frequency, the improvement comprising an electronic arrangement associated with said substation on initiation cf a call therefrom for amplifying only currents of said particular frequency and for suppressing currents cf any other frequency, and means operated only by the amplified currents for enabling the extension of a connection from said substation if the number of said amplified currents correspond to a. predetermined coin value.

References Cited in the file of this patent UNITED STATES PATENTS 1863,322 Bennett Inne 14, 1932 1982735 Heitsmith Dec. 4, 1934 2000,804 Wehren May 7, 1935 2224,702 Seidel Dec. 10, 1940 2729703 Faulkner Jan. 3, 1956 FOREIGN PATENTS 604,547 Great Britain July 6, 1948 

